Band device for a wheel rim

ABSTRACT

An assembly ( 10 ) for location around a wheel rim ( 32 ) comprises an annular support band ( 12 ) being formed of a relatively inextensible material. The support band ( 12 ) is split at at least one circumferential location to define a pair of opposed ends ( 16, 18 ). Adjustment means ( 24, 26, 28 ) are operably connected to said opposed ends ( 16, 18 ) for enabling adjustment of the diameter of the support band ( 12 ), and spacing means ( 14 ) depend from the radially inner face ( 34 ) of the support band ( 12 ). The spacing means ( 14 ) is formed from a relatively non-compressible material and, in use, is seated upon the wheel rim ( 32 ) to maintain the support band ( 12 ) in a spaced apart relationship with the wheel rim ( 32 ). The assembly may be adapted for use as a runflat assembly or as a beadlock assembly.

[0001] The invention relates to an assembly for incorporation about avehicle wheel rim, which is suitable for use as either a runflatassembly or a beadlock assembly, depending on the structure of the wheelrim.

[0002] A vehicle wheel normally comprises a pneumatic tyre supportedupon a wheel rim. The wheel rim usually includes a pair of axiallyspaced apart tyre seats against which the beads of the tyre are seatedin use.

[0003] In between the tyre seats of a one piece wheel, the wheel rimusually includes a well which, during fitting and removal of the tyre,receives the beads of the tyre to enable them to be passed over the tyreseats.

[0004] In the event of a tyre puncture, whilst the wheel is rotating(herein referred to as a “runflat operation”), it is possible for thetyre, if sufficiently deflated, to come off of the wheel rim due to thetyre beads entering the well. If this happens, steerage control of thewheel, and hence the vehicle, is lost.

[0005] It is known to provide a runflat assembly which during fitting ofa tyre on a wheel rim, are fitted to block-off the well and therebyprevent the beads of the tyre entering the well.

[0006] It is important, once a runflat assembly has been fitted, that itdoes not become loose within the tyre, particularly in the event of thedeflation of the tyre. Also, when deflation has occurred, it should besufficiently robust to support the tyre beads and prevent them fromentering the well or deforming the runflat assembly.

[0007] These requirements necessarily mean that the runflat assembly hasto be a good fit within the well of the wheel rim.

[0008] Unfortunately, there are a large number of differentdesigns/shapes of wheel rims for vehicles, and so usually specificrunflat assemblies are tailor made for particular designs of wheel rims.

[0009] In addition to the variety of designs/shapes of wheel rims, thematerials from which the wheel rims are made can vary also. For example,wheel rims are commonly made from pressed steel or cast from a suitablealloy. This means that the runflat assemblies also have to be tailormade to accommodate the different materials from which the wheel rimsare made.

[0010] It is not necessary to provide a well between the tyre seats oftwo piece and multipiece wheels, because a tyre is fitted to the wheelrim of such a wheel before the components of the wheel are securedtogether.

[0011] Multipiece wheels are primarily used in heavy duty and/ormilitary applications. In such applications there is often a requirementfor the vehicle to be ran with tyres at low pressures in order to obtainextra traction and/or flotation when required, e.g. in sand (militarydesert applications) or muddy conditions.

[0012] These vehicles are often fitted with a Central Tyre InflationSystem so that the tyres can be significantly reduced in pressure andthen re-inflated whilst on the move.

[0013] When the tyres are fully inflated, the beads of the tyre areretained in position, against the tyre seats, by the pressure of the airwithin the tyre. However, when the tyres are run at a low pressure,there is a risk that the tyre beads will move inwards, towards oneanother, across the wheel rim because the air pressure within the tyreis not sufficient to retain the tyre beads in position.

[0014] This creates a similar situation to a blowout, because the tyrewill instantaneously, and fully, deflate.

[0015] When this occurs the Central Tyre Inflation System becomesineffective and the tyre cannot be re-inflated without removal from thevehicle.

[0016] An additional hazard, especially when the tyre is used on sand,mud or water, is that sand/mud/water will get into the tyre. This meansthat the tyre must be completely removed from the wheel and cleanedbefore it is re-fitted and re-inflated.

[0017] It is known to provide a beadlock that is fitted around the wheelrim of a multipiece wheel between the beads of a tyre and thereby retainthe beads of the tyre spaced apart from each other, even when airpressure in the tyre is reduced.

[0018] A beadlock can be fitted to a two piece or multipiece wheel,whereas it cannot be fitted to a single piece wheel provided with awell. This is because the provision of the beadlock would make itimpossible to fit a tyre to the single piece wheel.

[0019] The beadlock is fitted to the wheel so that it is a tight fitbetween the inner sections of the tyre's beads, and it is usually fittedunder pressure. The beadlock improves traction in extreme conditionsbecause it helps to prevent the tyre from slipping around the wheelunder traction, and during braking conditions.

[0020] Known beadlocks are positioned between the beads of a tyre beforethe tyre is fitted to a two piece or multipiece wheel. They are oftenmade of either a rubber or plastic ring, and are difficult to fit,having to be twisted and/or compressed to be able to be positionedinside a tyre. During fitting of the tyre, the tyre, with a beadlock inposition, is put over the wheel rim, and the complete assembly is forceddown over the rim using a press.

[0021] This means that the beadlock must be tailor made to fit aparticular tyre and a particular wheel rim. This is because it is notpossible to adjust the beadlock once it is fitted to a wheel, within atyre.

[0022] According to a first aspect of the invention an assembly forlocation around a wheel rim is provided, the assembly comprising anannular support band being formed of a relatively inextensible materialand being split at at least one circumferential location to define apair of opposed ends, adjustment means operably associated with thesupport band for enabling adjustment of the diameter of the supportband, and spacing means depending from the radially inner face of thesupport band, the spacing means being formed from a relatively tough,load-bearing, nonmetallic material which in use is seated upon the wheelrim and maintains the support band in a spaced apart relationship withthe wheel rim.

[0023] An advantage of the invention is that the assembly can be usedwith wheel rims that are manufactured from a variety of materials,including wheel rims that are cast from an alloy. This is because thesupport band formed from a relatively inextensible material, such assteel, is supported in a spaced relationship with the wheel rim by thespacing means. The lack of contact between the support band and thewheel rim prevents corrosion that may otherwise occur as a result ofdissimilar metal contact. It also prevents the support band from rubbingagainst the wheel rim that may create sharp edges on the support bandand/or scratch the surface of the wheel rim. The spacing means formedfrom a relatively tough, load-bearing, non-metallic material is unlikelyto scratch the wheel rim and/or cause any corrosion of the wheel rim.

[0024] The support band can also be easily modified, using theadjustment means, to fit wheel rims having different circumferentialsizes. For example, when the support band is used in a runflat assembly,the support band can be adjusted to fit the wheel rim and prevent therunflat assembly from rotating about the wheel rim.

[0025] In a first particular embodiment of the invention, the assemblyis adapted for location in a well of a wheel rim.

[0026] In this embodiment of the invention, the support band may have anaxial width substantially the same as the width of the mouth of a well.The spacing means may also have a shape, in cross-section, which enablesit to be seated upon the floor of the well and maintain the support bandin a spaced apart relationship with the wheel rim.

[0027] The support band of this embodiment of the invention is suitablefor use as a runflat assembly.

[0028] An advantage of this particular embodiment of the invention isthat the runflat assembly can be easily modified to cater for wheel rimshaving different shaped wells, by exchanging the spacing means for aspacing means having a different cross-sectional shape/size/depth.

[0029] For example, the spacing means may be replaced with a relativelydeeper spacing means for use in a relatively deeper well.

[0030] In a second particular embodiment of the invention, the supportband is adapted to resiliently urge the beads of a tyre into abutmentwith the wheel rim.

[0031] The support band may have an axial width substantially the sameas the width of the wheel rim.

[0032] An advantage of this embodiment of the invention is that it isnot necessary to use a support band that is tailor made to fit aroundthe wheel rim. This is because the support band can be adjusted usingthe adjustment means to fit wheel rims having varying circumferentialsizes.

[0033] It is also advantageous because the split in the support bandallows the support band to be flexed into a smaller circumference whenthe adjustment means are removed. This provides a much simpler, andeasy, method of fitting the support band within the tyre. It is notnecessary to twist and/or compress the support band in order to fit itwithin the tyre.

[0034] The support band according to the second embodiment of theinvention may include a strip positioned on each of its two outerperipheral edges, the strip being moulded from a resilient material.

[0035] The strips prevent the support band from cutting into orotherwise damaging the tyre. Also, friction between the strips and thebeads of the tyre assists in holding the tyre to the rim, improvingtraction and improving braking resistance.

[0036] They also reduce the risk of water/mud/sand or any other debrisfrom getting into the tyre.

[0037] The strips may include formations along their outer edges forimproving grip between the strips and the tyre beads. In particular, thestrips may include serrations along their outer edges.

[0038] In either of these two embodiments of the invention, the spacingmeans may include a plurality of feet, wherein each foot is detachablyengageable with the support band.

[0039] The use of such feet is advantageous because they allow a user toprovide a tailored fit easily, and simply, by choosing which feet wouldbe suitable for a particular wheel rim before fitting them to thesupport band.

[0040] This therefore provides the runflat assembly with a certaindegree of versatility because the detachably engageable feet allow therunflat assembly to be modified easily to fit wheel rims having wells ofdifferent shape, size and depth.

[0041] For example, the feet may be replaced with relatively longer feetin order to modify the assembly for use in a relatively deeper well.

[0042] Each foot preferably includes at least one indicating means bywhich a user can determine the cross-sectional shape/size/depth and/orweight of the foot.

[0043] This allows a user to quickly, and easily, determine whether aparticular foot is suitable for use in a particular wheel rim.

[0044] For example, feet that have a cross-sectional shape correspondingto the shape of the well of a first wheel rim may be red, whereas feetthat have a cross-sectional shape corresponding to the shape of the wellof a second wheel rim may be blue, i.e. the feet may be colour coded.

[0045] Where the spacing means includes a plurality of feet, then atleast one of the feet may be hollow and may include at least onemonitoring device and at least one transmitting device. Such monitoringand transmitting devices are known per se.

[0046] The use of such a hollow foot, in a runflat/bead lock assemblyfitted to a wheel, may allow an onboard computer controlling thefunction of components about a vehicle to which the wheel is attached,to determine certain parameters concerning the wheel. For example, themonitoring device may monitor the ambient temperature within the well ofthe wheel rim, inflation pressure of the tyre or the rotational speed ofthe wheel during movement of the vehicle.

[0047] The use of such a hollow foot is advantageous when it is used ina runflat assembly because it houses the monitoring and transmittingdevices within the well of the wheel rim, below the support band. Thismeans that during fitting of a tyre on the wheel the support bandprotects the monitoring and transmitting devices.

[0048] In further embodiments the annular support band may include aplurality of apertures that are spaced about, and extend betweenopposing faces of, the support band. Each foot may then be detachablyengaged with the support band by detachably engaging at least a portionof the foot in one of the apertures.

[0049] The use of such apertures allows a user to determine the number,and location, of feet that are provided around the assembly. This meansthat a user can, to a certain extent, control the overall weight of theassembly. It also allows the user to balance the weight of the assembly.For example, feet having different weight may be provided at differentpositions around the support band in order to balance the weight of thesupport band. This simplifies the balancing of the wheel after a tyrehas been fitted, because it reduces balancing of the wheel that mayotherwise be required as a result of the use of the assembly.

[0050] It also allows a user to easily engage or disengage each footwith the support band as required. It thereby reduces the risk of anyfeet becoming disengaged whilst the assembly is fitted, and whilst it isin use. It also allows a user to replace a foot easily if it shouldbecome damaged, rather than having to replace the entire assembly.

[0051] The apertures themselves are also advantageous because theyreduce the overall weight of the support band, without reducing itseffective surface area. They thus reduce the overall weight of theassembly without effecting its function in, for example, a runflatoperation.

[0052] When the support band is used in a runflat assembly, theapertures in the support band may be offset in relation to the centre ofthe band to take account of wheel rims having off-centre wells.

[0053] Engaging a portion of each foot in an aperture in the supportband is advantageous because it means that the transmitting portion of atransmitting device housed in a hollow foot, may be positioned in theengaging portion of the hollow foot. This ensures that the transmittingportion is not shielded by the support band, so allowing thetransmitting device to communicate with any receivers or transmittersthat are positioned externally of the wheel.

[0054] Each of the plurality of apertures is preferably circular inshape and each foot preferably includes an engaging portion that iscylindrical in shape and is detachably engageable within one of thecircular apertures. The engaging portion of each foot may include arounded free end that in use protrudes through a respective circularaperture.

[0055] The use of engaging portions having rounded free ends isadvantageous because it provides the runflat assembly with asubstantially smooth radially outer surface, substantially free from anyedges, when the feet are detachably engaged with the support band.

[0056] A bridge may be fitted across any apertures in the opposed endsof the support band through which the adjustment means may be insertedand adjusted. Such a bridge member may in use extend across the gapbetween the opposed ends and may include a terry clip to secure it inposition in the apertures with respect to the support band. The bridgemember presents a substantially smooth radially outer surface and helpsto ensure that the radially outer surface of the support band has asmooth surface.

[0057] The provision of a smooth radially outer surface of the supportband means that an inner tube used within a tyre fitted to the wheel isless likely to become damaged. This is because there are no edges thatmay otherwise damage the tube, or impede the tyre during inflation.Also, the location of the rounded ends of the engaging portions in theapertures of the support band prevents the tube from being forcedthrough any of the apertures during inflation of the inner tube.

[0058] In some embodiments of the invention, the support band may besplit at two, equally spaced apart, circumferential locations. Thisallows further adjustment of the circumference of the support band.

[0059] In other embodiments of the invention, each of the opposed endsof the support band may include a curved lip portion. Such curved lipportions increase the strength and prevent bending of the ends of theband if fixings are overtightened, or stressed, for example, during arunflat operation. In situations wherein the support band isovertightened, the annular support band is pulled tighter into the wellof the wheel rim. In a severe overtightening situation, the adjustingmeans between opposed ends of the band breaks before the curved lipportions become completely ‘unfurled’ and thereby damaged so that itcould be dangerous in use without the user being aware.

[0060] Each of the curved lip portions may include an ancillary spacermeans formed from a plastics material in the form of a button or limbthat depends from the radially inner surface of the lip portion, at itsfree end. The use of such ancillary spacer means is advantageous becausein use they may lie in contact with the floor of the well of a wheel rimwhen used in a runflat assembly, or in contact with the wheel rim whenused in a beadlock. The ancillary spacer means thus provide extrasupport at the opposed ends, where it may not be possible to fit any ofthe spacing means mentioned previously, and thereby ensure that thesupport band remains in a spaced apart relationship with the wheel rim,particularly during a runflat operation. The ancillary spacer meansprevent the support band from contacting the well of the wheel rim, andthus compliment the effect of the spacer means formed from a relativelytough, load-bearing, non-metallic material, preventing metal to metalcontact, corrosion and scratching.

[0061] The ancillary spacer means are fitted to the free ends of thecurved lip portions to ensure that they do not interfere with theadjustment means.

[0062] The ancillary spacer means are preferably detachable to allowmodification of the assembly to fit wheel rims having wells of differentshape, size and/or depth.

[0063] For example, the ancillary spacer means may be changed forrelatively longer or shorter ancillary spacer means when the assembly isused in a relatively deeper or shallower well in a wheel rim.

[0064] The adjustment means in some embodiments of the invention may bespring biased. The use of such spring biasing is particularlyadvantageous when the support band is fitted as a beadlock. This isbecause the spring biasing means that it is not necessary to pre-fit thesupport band round the wheel rim before fitting it within the tyre.

[0065] According to a second aspect of the invention there is providedan assembly for location around a wheel rim comprising an annularsupport band being formed of a relatively inextensible material andbeing split at at least one circumferential location to define a pair ofopposed ends, adjustment means operably associated with the support bandfor enabling adjustment of the diameter of the support band, and spacingmeans depending from the radially inner face of the support band, thespacing means being formed from a plurality of feet detachablyengageable with the support band.

[0066] Preferred embodiments of the invention will now be described, byway of non-limiting examples, with reference to the accompanyingdrawings in which:

[0067]FIGS. 1 and 2 shows an assembly in accordance with an embodimentof the invention;

[0068]FIG. 3 shows the assembly of FIG. 2 along the line A-A when it isfitted to a wheel rim;

[0069]FIGS. 4a and 4 b show a spacing means in accordance with anembodiment of the invention;

[0070]FIG. 5 shows an assembly according to a further embodiment of theinvention;

[0071]FIGS. 6a-6 c show partial views of the assembly of FIG. 5;

[0072]FIG. 7 shows a bridge in accordance with an embodiment of theinvention;

[0073]FIG. 8 shows an assembly in accordance with a yet furtherembodiment of the invention;

[0074]FIG. 9 shows the assembly of FIG. 8 along the line B-B when it isfitted to a wheel rim;

[0075]FIGS. 10 and 11 show partial views of alternative arrangements ofthe assembly of FIG. 8;

[0076]FIG. 12 shows a support band in accordance with an embodiment ofthe invention;

[0077]FIGS. 13 and 14 show an assembly in accordance with anotherembodiment of the invention; and

[0078]FIGS. 15 and 16 show an adjustment means in accordance with anembodiment of the invention.

[0079] A runflat assembly 10 according to an embodiment of the inventionis shown in FIGS. 1 and 2.

[0080] The runflat assembly 10 includes a support band 12 formed from arelatively inextensible material, such as steel, and a plurality of feet14 formed from a relatively tough, load-bearing, non-metallic material,such as high density polyethylene or glass-filled nylon.

[0081] The support band 12 is split at one point about itscircumference, forming two opposed ends 16,18 of the support band 12.Each of the opposed ends 16,18 includes a curved lip portion 20 thatcurves inwardly, towards the centre of the support band 12.

[0082] As well as a curved lip portion 20, each of the opposed ends16,18 also includes a cross-shaped aperture 22 (FIG. 2), and the opposedends 16,18 are operably connected to each other by inserting anadjustment bolt 24 through the respective apertures 22 in the opposedends 16,18.

[0083] The adjustment bolt 24 is screw threaded, and is provided with abolt head 26 at one end, and a worm gear mechanism 28 at the other end.The worm gear mechanism 28 provides means by which the operable lengthof the bolt 24 can be adjusted in order to adjust the circumference ofthe support band 12, as will be described later.

[0084] The axial width W of the support band 12 substantiallycorresponds to the width of the mouth of a well 30 in a wheel rim 32(FIG. 3) about which the runflat assembly 10 is to be fitted.

[0085] The plurality of feet 14 depend, at spaced apart locations, fromthe radially inner face 34 of the support band 12. The specific locationand identity of the feet 14 about the circumference of the support band12 may be determined by the weight of each of the feet 14, in order tobalance the weight of the runflat assembly 10 about the wheel rim 32 towhich it is to be fitted.

[0086] As shown in FIG. 2, the support band 12 includes a plurality ofcircular shaped apertures 36 spaced apart about its circumference.

[0087] The apertures 36 may be offset from the centre of the supportband 12 to take account of wheel rims having off-centre positionedwells.

[0088] As shown in FIG. 4a, each foot 14 is frustoconical in shape andincludes first and second opposing flat surfaces 38,40. The first,relatively smaller, flat surface 38 acts as a base and, in use, rests onthe floor of a well 30 in a wheel rim 32.

[0089] A cylindrical engaging portion 42 projects from the second,relatively larger, flat surface 40. The diameter of the engaging portion42 corresponds to the diameter of each of the apertures 36 in thesupport band 12.

[0090] The engaging portion 42 of each foot 14 is detachably engaged ina respective aperture 36 in the support band 12 in a push fit manner.This allows, for example, each foot 14 to be replaced by a relativelylonger or shorter foot 14 in the event that the assembly 10 is to beused in a relatively deeper or shallower well.

[0091] The free end 44 of the engaging portion 42 that protrudes througha respective aperture 36 in the support band 12 is rounded so that theradially outer surface of the support band 12 is substantially free ofany edges, as shown in FIG. 4b.

[0092] When the runflat assembly 10 is fitted around the wheel rim 32 ofa wheel, the support band 12 is positioned so that it extends around thewheel rim 32 in the mouth of the well 30, as shown in FIG. 3. Theoperable length of the bolt 24 is adjusted so that the support band 12is tightened about the wheel rim 32, preventing the runflat assembly 10from rotating about the circumference of the wheel rim 32.

[0093] Tightening of the support band 12 about the wheel rim 32 forcesthe feet 14 tighter against the wheel rim 32 so that they become seatedon the floor 31 of the well 30.

[0094] When the support band 12 is tightened sufficiently, the feet 14support the support band 12 in a spaced relationship with the wheel rim32.

[0095] This ensures that the support band 12 does not lie in contactwith the wheel rim 32. It also ensures that the support band 12 isretained in the correct position so that in the event of a runflatoperation, the support band 12 prevents the beads of a pneumatic tyrefitted about the wheel rim 32, from entering the well 30.

[0096] The material from which the feet 14 are formed prevents them frombecoming squashed within the well 30, and ensures that the feet 14support the support band 12 correctly.

[0097] In other embodiments of the invention, at least one of the feet14 may be hollow and contain at least one monitoring device and at leastone transmitting device.

[0098] The use of a hollow foot 14 allows any monitoring andtransmitting devices to be housed, in use, below the support band 12, inthe well 30 of the wheel rim 32. This means that during fitting of atyre to the wheel, the devices are protected by the support band 12, andare not damaged by forcing the beads of the tyre across the radiallyouter surface of the support band 12.

[0099] The transmitting portion of any transmitting device may bepositioned within the cylindrical engaging portion 42 of the hollow foot14. This means that the transmitting portion remains protected by thehollow foot 14, during fitting of a tyre. However, it alsoadvantageously means that the steel support band 12 does not shield thetransmitting portion, and so the transmitting device is able tocommunicate with any transmitters and receivers located externally ofthe well in the wheel rim 32.

[0100] In yet further embodiments of the invention each foot includes atleast one indicating means. Such indicating means differentiate betweenfeet having different cross-sectional shape, size and/or depth. Forexample feet having a first cross-sectional shape may be a differentcolour to feet having a second cross-sectional shape and so on. Theindicating means may also differentiate between feet having differentweight that may be used when balancing the weight of the runflatassembly.

[0101] This may have advantages in fitting centres because the centremay have an array of support bands having different axial widths and anarray of different but identifiable feet. A fitter can then easilydetermine which feet he must use in combination with a particular axialwidth of support band for a runflat assembly to be fitted to aparticular wheel rim.

[0102] A runflat assembly 10 according to a further embodiment of theinvention is shown in FIG. 5.

[0103] Once again the runflat assembly 10 includes an annular supportband 12 and a plurality of feet 14 depending from the radially innerface 34 of the support band 12. However, the support band 12 accordingto this embodiment of the invention is split twice at equally spacedapart circumferential locations.

[0104] The support band 12 according to this embodiment of the inventiontherefore includes two sets of opposed ends 16,18;16′,18′. The opposedends 16,18;16′18′ of each set are operably connected to each other by abolt 24,24′.

[0105] As in the previous embodiment, each bolt 24,24′ is threaded andis provided with a bolt head 26,26′ at one end, and a worm gearmechanism 28,28′ at the other end.

[0106] The operable length of each bolt 24,24′ is adjustable using therespective worm gear mechanism 28,28′ to allow the circumferential sizeof the support band 12 to be adjusted so as to obtain a suitable fitabout the wheel rim 32 of a wheel.

[0107] In this embodiment, and in the previous embodiment, the opposedends 16,18 of the support band 12 include curved lip portions 20. Thecurved lip portions 20 curve inwardly, towards the centre of the supportband 12.

[0108] Each opposed end 16,18 includes a cross-shaped aperture 22 asshown in FIG. 6a. Each cross-shaped aperture 22 includes a cross portion46 that extends across the width of the support band 12, and first andsecond leg portions 48,50 that extend from opposing sides of the crossportion 46, along the length of the support band 12.

[0109] The cross-shaped apertures 22 of opposed ends 16,18 form a mirrorimage of each other when viewed from the side, (FIG. 6a), so that thefirst leg portions 48 of the two apertures 22 extend towards oneanother, away from their respective cross portions 46.

[0110] When the support band 12 is positioned about a wheel rim 32, thebolt 24 is inserted into position by passing it lengthwise through theapertures 22 of the opposed ends 16,18.

[0111] Two cylindrical retainer members are slidably mounted on the bolt24 between the bolt head 26 and the worm gear mechanism 28. When thebolt 24 is inserted through the apertures 22 in the opposed ends 16,18of the support band, one of the retainers is positioned on the bolt 24adjacent to the bolt head 26, and the other retainer is positionedadjacent to the worm gear mechanism 28.

[0112] The bolt head 26 and its corresponding retainer member passthrough the cross portion 46 of one of the apertures 22 in one of theopposed ends 16 whilst the worm gear mechanism 24 and its correspondingretainer member pass through the cross portion 46 of the aperture 22 inthe other opposed end 18. The bolt 24 passes through the first andsecond leg portions 48,50 as required.

[0113] The worm gear mechanism 28 includes a standard hexagonal bolthead arrangement 29. This bolt head arrangement 29 allows a user totighten the support band 12 about the wheel rim 32 directly from theside of the wheel. The bolt head arrangement 29 allows the user to use anormal socket/socket set and torque wrench.

[0114] The operable length of the bolt 24, between the bolt head 26 andthe worm gear mechanism 28 is adjusted by turning the hexagonal bolthead of the hexagonal bolt head arrangement 29. This forces the wormgear mechanism along the bolt 24 either towards or away from the bolthead 26 depending on the direction in which the hexagonal bolt head isturned.

[0115] The bolt head arrangement 29 faces outwards through the relevantaperture 22 allowing easy access to the bolt head arrangement 29. Thisarrangement is advantageous over commonly known bolt arrangements usedto adjust the operable length of the bolt in which a round headed Allenkey is often required to turn the bolt i.e. by inserting an end of theAllen key into an aperture in the bolt head. The arrangement makesfitting of the runflat assembly much more simple, fast and an easyone-man operation.

[0116] When the bolt 24 is inserted through the apertures 22 in opposedends 16,18 of the support band, the worm gear mechanism 28 must bepositioned on the bolt 24 so that the operable length of the bolt,between the retainer members associated with the bolt head 26 and theworm gear mechanism 28, corresponds to the distance between the crossportions 46 of the apertures 22.

[0117] In use, adjustment of the operable length of the bolt 24 totighten the support band 12 about the wheel rim 32 causes the bolt head26 and the worm gear mechanism 28, and their corresponding retainermembers, to be drawn against the inner surface of the respective curvedportion 20 of the opposed ends 16,18. This is shown in FIG. 6b.

[0118] This means that the bolt head 26 and the worm gear mechanism 28are retained between the respective first leg portions 48 of theapertures 22 and the respective curved portions 20 of the opposed ends16,18. This prevents them from passing back through the cross portions46 of the apertures 22.

[0119] In an overtightening situation, the bolt 24 continues to betightened even when the support band 12 is tight against the wheel rim32. This forces the curved portions of known support bands to unfurl asa result, causing the bolt to be forced against the end of the legportion of each of the apertures. This may cause the curved portions tounfurl completely, possibly breaking, and it may also strain the curvedportions so weakening them.

[0120] The length of the curved portion 20 of each opposed end 16,18 issuch that if the bolt 24 is overtightened, so forcing the opposed ends16,18 closer together when the support band 12 is tight against thewheel rim 32, then the curved ends 20 do not unfurl completely beforethey abut against each other, as shown in cross-section in FIG. 6c.

[0121] When the opposed ends 16,18 are abutted against each other theyprevent each other from unfurling any further in response to furtheradjustment of the operable length of the bolt 24.

[0122] Also the first leg portion 48 of each aperture 22 extends alongthe length of the curved portion 20 so that if the bolt 24 is tightenedso that the opposed ends 16,18 abut each other then the bolt 24 is notforced against the ends 49 of the first leg portions 48, as shown inFIG. 6c. This prevents weakening of the curved portions 20. Furtheradjustment of the bolt 24, after the opposed ends 16,18 have abuttedeach other, therefore causes strain in the bolt 24 rather than in thecurved portions 20.

[0123] In embodiments wherein the support band 12 is split at twocircumferential locations, the length of each of the bolts 24,24′ can behalf that of a bolt 24 used in a support band 12 that is only splitonce, and continue to provide the same amount of adjustment. This isadvantageous because it means that as the worm gear mechanisms 28,28′progress along the length of the bolts 24,24′ then the free end of eachof the bolts 24,24′ does not protrude into the support band 12 as mayoccur when a longer bolt 24 is used in a support band 12 that is onlysplit once.

[0124] In embodiments of the invention, the radially inner surface ofeach of the curved lip portions 20 of the opposed ends 16,18 may beprovided with an ancillary spacer means in the form of a button 52formed from a plastics material (FIGS. 6b and 6 c). The button 52 issecured to the free end of each of the curved lip portion 20 sopreventing the button 52 from interfering with the bolt head 26 and theworm gear mechanism 28 of the adjustment bolt 24.

[0125] When the runflat assembly 10 is fitted to a wheel rim, thebuttons 52 provided on the radially inner surfaces of the curved lipportions 20 engage the floor 31 of the well 30 of the wheel rim 32. Theythus support the opposed ends 16,18 of the support band 12 in the spacedapart relationship with the wheel rim 32, particularly in a runflatoperation.

[0126] The ancillary spacer means are preferably detachable and in otherembodiments may take the form of elongate limb members. For example, thebuttons 52 may be replaced with limb members to modify the assembly 10for use in a relatively deeper well.

[0127] When adjustment of the bolt 24 has been completed, a bridge 54may be secured across the gap between the opposed ends 16,18, as shownin FIG. 7. The bridge 54 includes a terry clip that engages in theapertures 22 in the opposed ends 18,16 to secure the bridge 54 inposition. When fitted, the bridge 54, together with the projectingrounded free end 44 of the cylindrical engaging portion 42 of each ofthe feet 14 detachably engaged within the apertures 36, presents asmooth surface to ensure that the radially outer surface of the supportband 12 is smooth and substantially free from any edges.

[0128] In other embodiments of the invention the bolt 24 may be replacedby a conventional bolt arrangement in which a threaded bolt having abolt head is passed through an aperture in each of two cylindricalretainer members, and into a threaded nut, such as a nylock nut.

[0129] The operable length of the bolt according to such embodiments isadjusted by inserting an Allen key into the bolt head and turning it soas to turn the threaded bolt either into or out of the nut positioned atthe other end of the bolt.

[0130] As with the bolt 24 described in relation to the previousembodiments, the conventional bolt is passed through the apertures 22 inthe opposed ends 16,18 of the support band 12 so that when the operablelength of the bolt is adjusted, each of the retainer members are forcedinto, and retained within, the relevant curved lip portion of theopposed ends 16,18.

[0131] In other embodiments, the operable length of a threaded bolt maybe adjusted by fixing a sprocket, similar to a standard timing beltpulley, to the threaded bolt between the corresponding retainer membersof a bolt head and a nut provided at opposing ends of the bolt. A singlepiece of belt that includes a plurality of equidistantly spaced teethmay be provided around the sprocket so that the teeth on the belt engagebetween teeth on the sprocket.

[0132] The belt may be a single long piece of timing belt, and thedistance between the teeth on the belt may correspond to the distancebetween the teeth on the sprocket.

[0133] The operable length of the bolt may then be adjusted by pullingthe belt so that the teeth on the belt force the sprocket. Depending onwhich end of the belt is pulled, the belt and sprocket combinationcauses the bolt, fixed within an aperture through the centre of thesprocket, to be turned into, or out of, the nut.

[0134] The nut may be a nylock nut, and the sprocket may be fixed at acentral point along the length of the threaded bolt, or may be formed aspart of the threaded bolt.

[0135] This arrangement allows adjustment of the operable length of thebolt without having to insert an Allen key into the bolt head. It alsoallows the support band to be adjusted as far away from the wheel, andthus as far away from the restrictions of the tyre, as the length of thebelt will allow.

[0136] In yet further embodiments, a jubilee type clip may be used as anadjustment means to adjust the circumferential size of the support band12. However, whereas standard jubilee hose clips include tooth threadsextending perpendicular to the longitudinal axis of the band, thejubilee type clip according to such embodiments of the invention havetooth threads that extend at an acute angle to the longitudinal axis ofthe band, preferably at an angle of about 45°, and the correspondingworm gear drive mechanism on the clip band is set at an angle withrespect to the clip band.

[0137] In such embodiments the curved lip portions of the support band12 may not be necessary because the clip band may be positioned around awheel, over the top of the support band 12.

[0138] The worm gear mechanism is fixed to a first end of the clip band,and is engageable with the other end of the clip band. When the wormgear mechanism is engaged with the other end of the clip band, it may bemoved along the length of the clip band, so as to adjust thecicumferential size of the clip band, by turning an adjustment screw onthe worm gear mechanism. This forces the mechanism to draw itself alongthe clip band by engaging the tooth threads in the clip band.

[0139] By adjusting the circumferential size of the clip band when it isposition over the top of a support band around a wheel, the clip bandmay be pulled tight over the support band. This forces the feet intoposition on the wheel rim, and retains the support band in position.

[0140] The clip band is preferably positioned around a wheel rim, overthe top of the support band, so that the tooth threads are positioned onthe radially inner surface of the clip band. This means that when theworm gear mechanism is engaged with the other end of the clip band, theworm gear mechanism is located on the radially inner side of the clipband, preferably within a slot or recess formed in the support band 12.This ensures that a substantially smooth surface may be maintained overthe radially outer surface of the assembly.

[0141] Access to the adjustment screw on the worm gear mechanism may beprovided on the side of the clip band because the tooth threads are atan acute angle to the longitudinal axis of the clip band 45°. Thus thelongitudinal axis of the adjustment screw is also at an acute angle tothe longitudinal axis of the band and therefore allows a suitable longscrewdriver or other tool to be used to tighten the support band 12 withrelative ease, outside the confines of the tyre.

[0142] A beadlock 110 according to an embodiment of the invention isshown in FIG. 8. The beadlock 110 shown in FIG. 8 is substantially thesame as the runflat assembly 10 shown in FIG. 2.

[0143] The beadlock 110 includes an annular support band 112 formed froma relatively inextensible material, such as steel, and a plurality offeet 114 depending from the radially inner face 126 of the support band112. The feet 114 are formed from a relatively tough and load-bearing,non-metallic material such as high density polyethylene or glass-fillednylon.

[0144] The support band 112 is split at one point about itscircumference, forming two opposed ends 116,118 of the support band 112.Each of the opposed ends 116,118 includes a curved lip portion 120 thatcurves inwardly, towards the centre of the support band 112.

[0145] As well as a curved lip portion 120, each of the opposed ends116,118 also includes a cross-shaped aperture 122, and the opposed ends116,118 are operably connected to each other by inserting an adjustmentbolt 124 (not shown) through the respective apertures 122 in the opposedends 116,118.

[0146] The adjustment bolt 124 is substantially similar to the bolt 24described in respect of the previous embodiments. It is screw threaded,and is provided with a bolt head at one end, and a worm gear mechanismat the other end. The worm gear mechanism provides means by which theoperable length of the bolt 124 can be adjusted in order to adjust thecircumference of the support band 112, in a similar manner to thatdescribed earlier with reference to FIGS. 6a-6 c.

[0147] As described in relation to the previous embodiments, thecircumferential size of the support band 112 may be adjusted by using aconventional bolt arrangement, a bolt including a belt and sprocketarrangement or a jubilee clip type arrangement, rather than with thebolt and worm gear arrangement.

[0148] The axial width W of the support band 112 substantiallycorresponds to the width of the wheel rim 132 (FIG. 9) about which thebeadlock it to be fitted between the beads 131,133 of a tyre 130.

[0149] As in the runflat assembly described with reference to FIGS. 1and 2, the plurality of feet 114 depend, at spaced locations, from theradially inner face 134 of the support band 112.

[0150] The feet 114 are fitted within a plurality of circular apertures136 provided in the support band 112. The apertures 136 are spacedaround the circumference of, and extend between opposing faces of, thesupport band 112.

[0151] The feet 114 are similar to the feet 14 described earlier withreference to FIGS. 4a and 4 b. As shown in FIGS. 4a and 4 b, each of thefeet 114 is frustoconical in shape, and is provided with an engagingportion that push fittingly engages within an aperture 136.

[0152] The support band 112 of the beadlock 110 further includes twomoulded rubber strips 121,123 fitted to its peripheral edges.

[0153] The beadlock assembly 110 is initially pre-fitted around thecircumference of the wheel rim 132 to which a tyre 130 is to be fitted.The operable length of the bolt 124 is adjusted to provide a suitablefit around the wheel rim 132, so that the feet 114 are seated on thewheel rim. It is not necessary for the feet 114 to fit tight against thewheel rim 132, because in use, the tyre 130 holds the beadlock 110 inposition, and prevents the beadlock from rotating about the wheel rim132.

[0154] When the operable length of the bolt 124 has been adjusted sothat the circumference of the support band 112 provides a suitable fitaround the wheel rim 132, the support band 112 is removed from the wheelrim 132, without further adjustment of the operable length of the bolt124.

[0155] The material from which the support band 112 is made means thatit is possible to flex the opposed ends 116,118 of the support band 112towards one another. This allows the bolt head and the worm gearmechanism of the bolt 124 to move so that they can be passed through thecross-shaped apertures 122 in the opposed ends 116,118 of the supportband 112.

[0156] When the bolt 124 has been removed from the support band 112, thesupport band 112 can be flexed further to reduce its circumference byoverlapping the opposed ends 116,118. This allows the support band 112to be inserted through the circular opening on one side of the tyre 130so that it can be positioned around the inner circumference of the tyre130, between the beads 131,133 of the tyre 130.

[0157] When the support band 112 is inserted into the tyre 130, releaseof the opposing ends 116,118 allows the support band 112 to flex backtowards its original circumferential size within the tyre. However,before the support band 112 retains its original circumferential size,the bolt head and worm gear mechanism of the bolt 124 are reinsertedthrough the cross-shaped apertures 122 in the opposed ends 116,118. Thisallows the support band 112 to flex back to the circumferential sizethat it was adjusted to during the pre-fitting step.

[0158] The beadlock 110 is retained tightly between the beads 131,133 ofthe tyre 130, and the tyre and beadlock 110 are then placed over thewheel rim 132 in the normal manner i.e. by using a press.

[0159] When the tyre 130 is fitted to the wheel rim 132, the feet 114engage against the surface of the wheel rim 132, ensuring that thesupport band 112 maintains a spaced relationship with the wheel rim 132.They provide sufficient slippage to allow the beadlock 110 within thetyre 130 to be fitted to the wheel rim 132. However, they prevent thesupport band 112 from scratching the wheel rim, and prevent anycorrosion that may otherwise be caused by dis-similar metal contact.

[0160] As in previously described embodiments, at least one of the feet114 may be hollow, and may contain at least one monitoring device and atleast one transmitting device.

[0161] Also, the feet 114 may include at least one indicating means todifferentiate between feet 114 having different cross-sectional shape,size, depth and/or weight, as described in the previous embodiments.

[0162] The moulded rubber strips 121,123 around the peripheral edges ofthe support band 112 prevent the support band 112 from damaging the tyrebeads 131,133.

[0163] Each of the moulded rubber strips 121,123 includes an outer edge125 (FIGS. 10 and 11) that, in use, engages, via friction, with an innerportion of one of the tyre beads 131,133. The outer edge 125 may beformed substantially flat, as shown in FIG. 10. Alternatively, it may beformed with a plurality of serrations, as shown in FIG. 11.

[0164] In embodiments wherein the outer edge 125 of each of the mouldedrubber strips 121,123 is formed with a plurality of serrations, then theouter edge 125 may be shaped to provide a perfect fit on the respectivetyre bead 131,133.

[0165] In other embodiments, the outer edge 125 of each of the strips121,123 may be shaped so that is has a slightly smaller radius. In use,the beads 131,133 of a tyre automatically put pressure on the respectivemoulded rubber strips 121,123 when the strips 121,123 push against thebeads 131,133. This squeezes the slots 127 into which the support band112 is fitted in each of the strips 121,123, assisting the strips121,123 to grip their respective peripheral edge of the support band112.

[0166] Tooling for producing the strip may be adjustable to allow theslot 127 in each of the strips 121,123 to be adjusted. Such adjustmentscan then be made to take account of depth adjustment and smallvariations in wheel and/or tyre bead widths. It thereby allows thepressure applied by the beadlock 110 to beads 131,133 of a tyre 130 tobe adjusted.

[0167] The support band 112 may be split at two equally spaced apartcircumferential locations, as described previously with reference toFIG. 5.

[0168] In other embodiments of the invention, the support band 112 ofthe beadlock 110 may include two support bands 112 a,112 b weldedtogether along their adjacent edges, as shown in FIG. 12.

[0169] In such an embodiment of the invention, each of the support bands112 a,112 b may include a series of apertures 136 so that two side byside rows of feet 114 (not shown) may be provided along the length ofthe support band 112.

[0170] The provision of two side by side rows of feet 114 depending fromthe radially inner face of a support band 112 provides extra stability,particularly when the beadlock is used on a relatively wide wheel rim132.

[0171] The support band of the runflat assembly 10 described earlierwith reference to FIGS. 1 and 2, may be modified in a similar manner, soas to provide two rows of feet 14 and provide extra support andstability when the runflat assembly is located in a relatively widerwell of a wheel rim.

[0172] As shown in FIGS. 13 and 14, runflat assemblies 140 in which thesupport band 142 comprises two bands 142 a,142 b secured together sideby side along their adjacent edges, e.g. by welding, can be modified foruse as a beadlock. This is done by securing an elongate channel member150 across each pair of side by side feet 144, as shown in FIG. 14.

[0173] Each elongate channel member 150 is substantially C-shaped incross-section, and is open along one side, as shown in FIG. 14. It ispreferably formed from a lightweight material to ensure that the overallweight of the assembly is not greatly increased.

[0174] Each elongate channel member 150 is positioned so that the freeends of two side by side feet 144 pass through the open side of thechannel member 150, and are seated on an inner surface of a base portionof the channel member 150.

[0175] Two steel strips 154,156 may be mounted across the ends of thechannel members 150 positioned over the pairs of side by side feet 144,so that they extend parallel to the length of the support band 142.

[0176] Each of the steel strips 154,156 is substantially the same depthas the support band 142, and is provided along one peripheral edge witha moulded rubber strip 158. The moulded rubber strip 158 issubstantially the same as the moulded rubber strips 121,123 describedearlier, and can be formed with either a substantially flat engagingface 155, or a serrated engaging face, as described with reference toFIGS. 10 and 11.

[0177] When the runflat assembly 140 modified in this way is used as abeadlock, the assembly is located within a tyre 160 so that the rubberstrips 158 engage the beads 162 of the tyre, and retain the assembly 140in position in the tyre 160, as shown in FIG. 13.

[0178] An adjustment member 170 according to an embodiment of theinvention is shown in FIGS. 15 and 16.

[0179] The adjustment member 170 comprises an elongate threaded bolt 172provided with a bolt head 174 at one of its ends. A standard lock nut176 is screwed onto the threads of the bolt 172 at its other end.

[0180] Both the lock nut 176 and the bolt head 174 include a cylindricalretainer member, or roller, 178 in combination therewith. The operablelength of the threaded bolt 172 extends between the rollers 178.

[0181] The adjustment member 170 can be used in any of the previouslydescribed runflat and beadlock embodiments to adjust the circumferenceof the support band 12, in a similar manner to that described withreference to FIGS. 6a-6 c. In such use, the roller 178 portions of thelock nut 176 and of the bolt head 174 are drawn against curved lipportions of the support band to prevent disengagement of the adjustmentmember 170 from the support band.

[0182] The adjustment member 170 shown in FIGS. 15 and 16 includes acoiled spring 180 located between the bolt head 174 and its associatedroller 178. The coiled spring 180 ensures that the bolt head 174 and itsassociated roller 174 are maintained a predetermined distance apart fromeach other. Washers 182,184 are provided at either end of the coiledspring 180 to provide surfaces against which the spring 180 can engage.

[0183] The spring 180 allows the operable length of the bolt 172,between the rollers 178, to be temporarily increased without moving thelock nut 176. This is because the roller 178 associated with the bolthead 174 can be moved, against the bias of the spring 180, towards thebolt head 174, so increasing the operable length of the bolt 172.

[0184] When the sprung biassed roller 178 is released, the spring 180forces it back into its normal position, a predetermined distance awayfrom the bolt head 174, so returning the operable length of the bolt 172to its previous size.

[0185] This is particularly advantageous when used in a beadlock becauseit allows the operable length of the bolt 172 to be temporarilyincreased during fitting of the adjustment means to the support bandlocated within a tyre.

[0186] In other embodiments of the invention, the support band may beprovided with a strip on its radially outer surface that is formed froma resilient material. The strip may be a relatively thick rubber stripthat is bonded to the radially outer surface of the support band.

[0187] The use of such a strip on the radially outer surface of thesupport band is particularly advantageous during a runflat in anoff-road situation. This is because it would provide some shockabsorption.

[0188] A tyre rubber compatible grease may be used, inside the tyre, toreduce the temperature that is created as a result of friction betweenthe strip on the support band and the tyre.

1. An assembly for location around a wheel rim comprising an annularsupport band being formed of a relatively inextensible material andbeing split at at least one circumferential location to define a pair ofopposed ends, adjustment means operably associated with the support bandfor enabling adjustment of the diameter of the support band, saidsupport band being adapted to selectively receive a plurality of feetformed from a relatively tough, load-bearing, non-metallic material, toform a spacing means depending from the radially inner face of thesupport band which in use is seated upon the wheel rim and maintains thesupport band in a spaced apart relationship with the wheel rim, the feetbeing chosen from feet of different shapes and/or sizes to permittailoring of the spacing means to fit the wheel rim.
 2. An assembly asclaimed in claim 1 adapted for location in a well of the wheel rim. 3.An assembly as claimed in claim 2 wherein the support band has an axialwidth substantially the same as the width of the mouth of the well andeach of the feet forming the spacing means has a shape, incross-section, which enables it to be seated upon the floor of the welland, together with the other feet, maintain the support band in a spacedapart relationship with the wheel rim.
 4. An assembly as claimed inclaim 1 adapted to resiliently urge the beads of a tyre into abutmentwith the wheel rim.
 5. An assembly as claimed in claim 4 wherein thesupport band has an axial width substantially the same as the width ofthe wheel rim.
 6. An assembly as claimed in claim 5 wherein the supportband includes a strip positioned on each of its two outer peripheraledges, the strip being moulded from a resilient material.
 7. An assemblyas claimed in claim 6 wherein each of the moulded strips includesformations along its outer edges for improving grip between the stripsand the beads of the tyre.
 8. An assembly as claimed in claim 7 whereineach of the moulded strips includes serrations along its outer edges. 9.An assembly as claimed in any of claims 1 to 8 wherein each foot isdetachably engageable with the support band.
 10. An assembly as claimedin claim 9 wherein each foot includes at least one indicating means bywhich a user can determine the cross-sectional shape/size/depth and/orweight of the foot.
 11. An assembly as claimed in claim 9 or claim 10wherein at least one of said plurality of feet is hollow and includes atleast one monitoring device and at least one transmitting device.
 12. Anassembly as claimed in any preceding claim wherein the support band isadapted to receive said feet by the provision of a plurality ofapertures that are spaced about, and extend between opposing faces of,the support band.
 13. An assembly as claimed in claim 12 wherein atleast a portion of each foot is detachably engageable within one of theapertures in the support band.
 14. An assembly as claimed in claim 11 orclaims 12 or 13 when dependent on claim 11 wherein the transmittingportion of the at least one transmitting device is located in theportion of the hollow foot that is detachably engageable within one ofthe apertures in the support band.
 15. An assembly as claimed in claim12 or 13 wherein each of the plurality of apertures is circular inshape, and each foot includes an engaging portion that is cylindrical inshape and is detachably engageable within one of the apertures.
 16. Anassembly as claimed in claim 15 wherein the engaging portion includes arounded free end that in use protrudes through the respective aperture.17. An assembly as claimed in any preceding claim wherein the supportband is split at two, equally spaced apart, circumferential locations.18. An assembly as claimed in any preceding claim wherein each of theopposed ends of the support band includes a curved lip portion.
 19. Anassembly as claimed in claim 18 wherein each of the curved lip portionsincludes an ancillary spacer means formed from a plastics materialdepending from the radially inner surface of the lip portion at its freeend.
 20. An assembly as claimed in any preceding claim wherein theadjustment means is spring biased.
 21. A kit of parts for forming atailor-made runflat or bead lock assembly for location around a wheelrim comprising an annular support band formed of a relativelyinextensible material and split at at least one circumferential locationto define a pair of opposed ends, adjustment means and a plurality offeet of different shapes and/or sizes formed from a relatively tough,load-bearing, non-metallic material, wherein said support band isadapted to selectively receive one or more of the feet.
 22. A method ofproducing a runflat or beadlock assembly for fitment to a wheel rimcomprising the steps of selecting a plurality of feet from feet ofdifferent shapes and/or sizes, and fitting the selected feet to asupport band so that the feet depend from a radially inner face of thesupport band.